Strengthening effect of polyelectrolyte multilayers on highly filled paper

AbstractPolyelectrolyte multilayering (PEM) treatment is regarded as one of the surface modification techniques to increase paper strength. In this study, the strengthening effect of PEM treatment of highly filled paper was investigated. PEM treatment was performed on both fiber and filler with cationic starch and anionic polyacrylamide systems. Both approaches provided an improvement in the strength of filled paper. However, the strengthening effect of PEM treatment on fibers became weaker as filler content increased, whilst the PEM treatment on fillers was more effective in improving the strength of the highly filled paper. This was because PEM treatment on fillers improved bonding strength between fiber and filler as well as bonding strength between fillers. This was confirmed by the evaluation of specific debonding factor between fiber and filler, and the measurement of the breaking strength of dense film composed of fillers.

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Filler modified by a sequential encapsulation and preflocculation method and its effect on paper properties

Nordic Pulp & Paper Research Journal ◽

10.1515/npprj-2019-0047 ◽

2020 ◽

Vol 35 (1) ◽

pp. 89-95

Author(s):

Nannan Chen ◽

Lijun Wang ◽

Junchao Wen ◽

Xianping Yao ◽

Wenyan Zhao

Keyword(s):

Filler Content ◽

Strength Properties ◽

Paper Strength ◽

Cationic Starch ◽

Paper Properties ◽

Polyelectrolyte Complexes ◽

New Methods ◽

Charge Potential ◽

Filler Retention ◽

Anionic Polyacrylamide

AbstractIncreasing the filler content of sheet tends to decrease filler retention and paper strength properties. To overcome this problem and make better use of fillers, development of new methods on filler modification has never been stopped. In this study, filler modification was carried out by sequentially adding an anionic polyacrylamide, a cationic starch and a cationic polyacrylamide. It is believed that in this process, multiple polyelectrolyte complexes are formed which can not only encapsulate filler particles but also preflocculate the particles. The results showed that, compared to the single preflocculation treatment, the sequential encapsulation and preflocculation (SEP) treatment brought significantly larger particle size and higher surface charge potential of the filler, thus higher filler retention was achieved. When the modified fillers were used for papermaking and paper ash contents were controlled at the same level, the SEP modification was better in improving the tensile index, internal bond strength and tearing index of paper than the single preflocculation method, in addition, it maintained better paper formation, caused insignificant change on opacity of paper. It is believed that this newly developed SEP method is worthy of being applied to industrial scales in making various grades of filled paper.

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A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽

10.32964/tj18.11.653 ◽

2019 ◽

Vol 18 (11) ◽

pp. 653-664

Author(s):

IGNACIO DE SAN PIO ◽

KLAS G. JOHANSSON ◽

PAUL KROCHAK

Keyword(s):

Negative Impact ◽

High Strength ◽

Strength Properties ◽

Cellulose Microfibrils ◽

Paper Strength ◽

Flow Loop ◽

Cationic Starch ◽

Reflectance Measurement ◽

Drainage Rate ◽

Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

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Properties and Applications of Modified Bacterial Cellulose-Based Materials

Current Nanoscience ◽

10.2174/1573413716999201106145528 ◽

2020 ◽

Vol 16 ◽

Author(s):

Munair Badshah ◽

Hanif Ullah ◽

Fazli Wahid ◽

Taous Khan

Keyword(s):

Surface Modification ◽

Bacterial Cellulose ◽

Degree Of Polymerization ◽

Biomedical Science ◽

Hydroxyl Groups ◽

Market Demand ◽

Ideal Candidate ◽

Fibrous Network ◽

Potential Applications ◽

Surface Modification Techniques

Background: Bacterial cellulose (BC) is purest form of cellulose as it is free from pactin, lignin, hemicellulose and other active constituents associated with cellulose derived from plant sources. High biocompatibility and easy molding into desired shape make BC an ideal candidate for applications in biomedical field such as tissue engineering, wound healing and bone regeneration. In addition to this, BC has been widely studied for applications in the delivery of proteins and drugs in various forms via different routes. However, BC lacks therapeutic properties and resistance to free movement of small molecules i.e., gases and solvents. Therefore, modification of BC is required to meet the research ad market demand. Methods: We have searched the updated data relevant to as-synthesized and modified BC, properties and applications in various fields using Web of science, Science direct, Google and PubMed. Results: As-synthesized BC possesses properties such as high crystallinity, well organized fibrous network, higher degree of polymerization, and ability of being produced in swollen form. The large surface area with abundance of free accessible hydroxyl groups makes BC an ideal candidate for carrying out surface functionalization to enhance its features. The various reported surface modification techniques including, but not limited to, are amination, methylation and acetylation. Conclusion: In this review, we have highlighted various approaches made for BC surface modification. We have also reported enhancement in the properties of modified BC and potential applications in different fields ranging from biomedical science to drug delivery and paper-making to various electronic devices.

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Osseointegration Improvement of Co-Cr-Mo Alloy Produced by Additive Manufacturing

Pharmaceutics ◽

10.3390/pharmaceutics13050724 ◽

2021 ◽

Vol 13 (5) ◽

pp. 724

Author(s):

Amilton Iatecola ◽

Guilherme Arthur Longhitano ◽

Luiz Henrique Martinez Antunes ◽

André Luiz Jardini ◽

Emilio de Castro Miguel ◽

...

Keyword(s):

Surface Modification ◽

Additive Manufacturing ◽

Bone Ingrowth ◽

Orthopedic Implants ◽

Coated Sample ◽

High Mechanical Strength ◽

Coated Surface ◽

Surface Modification Techniques ◽

Almost All ◽

Cobalt Base

Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

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Review of titanium surface modification techniques and coatings for antibacterial applications

Acta Biomaterialia ◽

10.1016/j.actbio.2018.10.036 ◽

2019 ◽

Vol 83 ◽

pp. 37-54 ◽

Cited By ~ 158

Author(s):

H. Chouirfa ◽

H. Bouloussa ◽

V. Migonney ◽

C. Falentin-Daudré

Keyword(s):

Surface Modification ◽

Titanium Surface ◽

Surface Modification Techniques

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Near-Infrared Emitting Dual-Stimuli-Responsive Carbon Dots from Endogenous Bile Pigments

Nanoscale ◽

10.1039/d1nr01295a ◽

2021 ◽

Author(s):

Parinaz Fathi ◽

Parikshit Moitra ◽

Madeleine M. McDonald ◽

Mandy Brigitte Esch ◽

Dipanjan Pan

Keyword(s):

Surface Modification ◽

Carbon Dots ◽

Biomedical Applications ◽

Near Infrared ◽

Bile Pigments ◽

Careful Selection ◽

Stimuli Responsive ◽

Carbon Dot ◽

Surface Modification Techniques ◽

Selection Of

Carbon dots are biocompatible nanoparticles suitable for a variety of biomedical applications. Careful selection of carbon dot precursors and surface modification techniques has allowed for the development of carbon dots...

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Trend and Development in Laser Surface Modification for Enhanced Materials Properties

Additive Manufacturing ◽

10.4018/978-1-5225-9624-0.ch011 ◽

2020 ◽

pp. 271-295

Author(s):

Muhammed Olawale Hakeem Amuda ◽

Esther Titilayo Akinlabi

Keyword(s):

Surface Modification ◽

Computational Simulation ◽

Research Trends ◽

Functionally Graded ◽

Laser Surface ◽

Laser Surface Modification ◽

Process Dynamics ◽

Graded Material ◽

Surface Modification Techniques ◽

Simple Surface

This article presents a process review of the commonly available laser surface modification techniques for surface property enhancement. This is reinforced with the specific case treatment of research trends in relation to commonly treated materials. The progression from simple surface modification to the production of components with multifunctional characteristics known as functionally graded material is discussed in combination with emerging research focus on the computational simulation of laser surface modification for optimization of process dynamics.

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Structure and Surface Modification Techniques for Production of Value-Added Biocomposites

Value-Added Biocomposites ◽

10.1201/9781003137535-6 ◽

2021 ◽

pp. 125-156

Author(s):

Chaniga Chuensangjun ◽

Sarote Sirisansaneeyakul ◽

Takuya Kitaoka

Keyword(s):

Surface Modification ◽

Value Added ◽

Surface Modification Techniques

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Articulating Biomaterials

Processing Techniques and Tribological Behavior of Composite Materials - Advances in Chemical and Materials Engineering ◽

10.4018/978-1-4666-7530-8.ch009 ◽

2015 ◽

pp. 218-267 ◽

Cited By ~ 2

Author(s):

Vamsi Krishna Balla ◽

Mitun Das ◽

Someswar Datta ◽

Biswanath Kundu

Keyword(s):

Surface Modification ◽

Clinical Performance ◽

Decisive Role ◽

Surface Characteristics ◽

Surface Modification Techniques ◽

Biological Environment ◽

Surface Modified ◽

In Vivo Effects

This chapter examines the importance of surface characteristics such as microstructure, composition, crystallographic texture, and surface free energy in achieving desired biocompatibility and tribological properties thereby improving in vivo life of artificial articulating implants. Current implants often fail prematurely due to inadequate mechanical, tribological, biocompatibility, and osseointegration properties, apart from issues related to design and surgical procedures. For long-term in vivo stability, artificial implants intended for articulating joint replacement must exhibit long-term stable articulation surface without stimulating undesirable in vivo effects. Since the implant's surface plays a vital and decisive role in their response to biological environment, and vice versa, surface modification of implants assumes a significant importance. Therefore, overview on important surface modification techniques, their capabilities, properties of modified surfaces/implants are presented in the chapter. The clinical performance of surface modified implants and new surfaces for potential next-generation articulating implant applications are discussed at the end.

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